OPTIMIZATION OF PROCESSING TECHNIQUES FOR PRODUCTION OF OAT AND BARLEY MILKS

Abstract

Three trials have been carried out to prepare oat and barley milks with acceptable organoleptic properties and are free of unhealthy and harmful substances. These trails were (A) boiling of intact oat and barley grains after soaking but before disruption, (B) wet toasting of soaked grains before disruption, (C) disruption of soaked grains without heating. Effect of processing conditions (soaking, soaking + heating and soaking + toasting) and the ratio of grains to extracting medium on phytic acid content, % milk and % recovery of solids and protein in the resultant milk was studied. Some chemical and physical properties of the resultant milks were compared with that of cow milk (control). The results showed that process B has low yield of oat milk but higher recoveries of solids and protein in comparison with processes A and C whereas; process A was preferable to produce barley milk. Using sweet whey as an extracting medium instead of tap water caused an increase in total solids and protein contents and improved of organoleptic properties of resultant milks. About 13% on average of phytic acid was lost during the soaking of oat and barley grains. This reduction was increased to 16.56% after toasting of soaked oat grains while reached 21.73% after heating of soaked barley grains. Chemical analysis of oat, barley and cow milks showed that cow milk had higher fat and Ca contents than both oat and barley milks while, oat and barley milks contain more carbohydrates, phosphorus, potassium, iron and Zinc than dose cow milk. Cow milk and oat milk contain nearly identical amounts of protein and fiber is a big plus, dairy has none. With respect to the amino acid composition, isoleucine, methionine, threonine and tyrosin occurred at slightly lower levels in proteins of oat and barley milks than those of the FAO/WHO reference protein. Cow milk protein had slightly higher essential amino acids content than those in proteins of oat and barley milks. Both oat milk and barley milk exhibited higher viscosity and lower heat stability than those of cow milk whereas, titrable acidity and specific gravity values of these milks were approached those of cow milk.. Consequently, oat milk or barley milk can be a healthy choice for many peoples especially who are allergic to milk protein. Three trials have been carried out to prepare oat and barley milks with acceptable organoleptic properties and are free of unhealthy and harmful substances. These trails were (A) boiling of intact oat and barley grains after soaking but before disruption, (B) wet toasting of soaked grains before disruption, (C) disruption of soaked grains without heating. Effect of processing conditions (soaking, soaking + heating and soaking + toasting) and the ratio of grains to extracting medium on phytic acid content, % milk and % recovery of solids and protein in the resultant milk was studied. Some chemical and physical properties of the resultant milks were compared with that of cow milk (control). The results showed that process B has low yield of oat milk but higher recoveries of solids and protein in comparison with processes A and C whereas; process A was preferable to produce barley milk. Using sweet whey as an extracting medium instead of tap water caused an increase in total solids and protein contents and improved of organoleptic properties of resultant milks. About 13% on average of phytic acid was lost during the soaking of oat and barley grains. This reduction was increased to 16.56% after toasting of soaked oat grains while reached 21.73% after heating of soaked barley grains. Chemical analysis of oat, barley and cow milks showed that cow milk had higher fat and Ca contents than both oat and barley milks while, oat and barley milks contain more carbohydrates, phosphorus, potassium, iron and Zinc than dose cow milk. Cow milk and oat milk contain nearly identical amounts of protein and fiber is a big plus, dairy has none. With respect to the amino acid composition, isoleucine, methionine, threonine and tyrosin occurred at slightly lower levels in proteins of oat and barley milks than those of the FAO/WHO reference protein. Cow milk protein had slightly higher essential amino acids content than those in proteins of oat and barley milks. Both oat milk and barley milk exhibited higher viscosity and lower heat stability than those of cow milk whereas, titrable acidity and specific gravity values of these milks were approached those of cow milk.. Consequently, oat milk or barley milk can be a healthy choice for many peoples especially who are allergic to milk protein.